1. Field of the Invention
This invention relates generally to providing computer output to blind computer users and more particularly to providing means and method for allowing blind computer users to visualize computer graphic images and multiple screen windows in much the same way as these forms of computer output are visualized by persons with sight.
2. Background Prior Art
A number of electronically assisted or computerized reading systems have been proposed for use by the blind. Examples include German Patent Publication DE3901023 and U.S. Pat. No. 4,687,444.
The German publication teaches an optical scanner 11 mounted in a hand held device having a braille output matrix 5. The device is scanned across printed text which is "read" and "recognized" by a computer 3 and converted to braille for output to the user. No provision is made for handling non text graphics and icons.
The U.S. patent teaches a tape "reader" which converts text encoded onto a magnetic tape into braille output matrix 24. The tape is read into a buffer. The buffer is then read out to a braille matrix. The tape is commonly encoded in a braille code and can be amplified to drive the matrix actuators directly. Reading of the buffer is controlled by moving a mouse similar to those used with computers but there is only a horizontal distance output to control buffer addressing.
A device, called the Opticon, from Telesensory Company in Mountain View California, has the capability of translating the area surrounding the display cursor into a matrix of pins such that contrasting areas of the display will map to vibration of certain of the pins. The user places a finger of one hand on the pin matrix and the other hand holds and moves a mouse that causes the cursor to move about the display.
The original concept for the Opticon used a video camera that the user would scan across a paper document and then evolved thru camera lens changes to an ability to physically scan across a computer display. Further evolution was the substitution of a mouse driven cursor for the handheld camera. The pin matrix, however, remained a separate device that is touched by a finger of the other hand.
The computer workstation for sighted users has evolved from a simple character based display to displays of graphics, windows, and object oriented programming. This evolution continues with multimedia and mixed media screen presentations, voice annotations, and simulated prospective.
Likewise, the user interface to this graphical display has shifted from the keyboard towards the "mouse". The mouse allows the user to easily move from one area of the display to another, and by single and double clicking on it's button keys, to manipulate the objects upon which the mouse driven cursor lies.
An example of such an object manipulation is "drag and drop" whereby an object that represents a document, such as a musical composition, can be captured and dragged to an object which represents a printer and the document is printed; or dragged to a representation of a phonograph and the document is transposed to an audio rendition of the music.
A paper document is a fixation of information to a substrate. That is the text and/or graphics do not move once placed upon the paper. That is conditionally true also for a character based computer display. A document, though scrollable, is typically positional stable upon the screen. Thus it is reasonable to accept the learned ability of a blind user to be able to read text characters by feeling their impressions as simulated by a tactile readout device.
As described above with respect to a sighted user, windows appear, move, expand, and contract. Likewise menus pull-down, and scroll bars and radio buttons wait to be actuated. Icons represent objects to be manipulated. Objects, by dragging and dropping, interact with other objects and things happen--like printing, speech articulation, new object formation, etc.
The blind user requires a more sophisticated approach to interaction with this new technology. The compensatory enhancement of the sense of touch is not alone sufficient for spatial orientation when the information presented is free flowing, non-restrained, and particularly non-character representations.